Known directory services (DSs) include directory information trees (DITs) arranged to represent and organize directory service (DS) objects according to the location of the particular objects within the network (e.g. remote geographic locations such as Miami office, New York office, and Los Angeles office within an organization, or even non-permanently linked LAN A, LAN B, and LAN C).
Organizing directory services, or any resource locating mechanisms, according to location works well when searches for network resources and attempts to access the network resources are closely tied to network location, such as when the Research and Development resources are maintained at location X, sales and marketing at location Y, etc. Novell Netware 4.0 includes a directory service wherein a network directory of resources is divided at a highest level according to location and then at lower levels to particular organizational groups of resources at each of the locations provided at the highest level.
However, problems arise in locating resources when an organization's groups are not localized (to fit the organization of the directory). In such instances resources associated with a particular group, such as a "research and development" group, within an organization are present at a number of nodes within a DIT for the company due to the "geographic" diversity of the group. Searching for particular resources requires searching the various locations of the DIT.
Known directory service arrangement schemes also include DITs that represent and organize directory service objects according to a business structure of an organization (e.g. research and development, accounting, marketing, sales, etc . . . ). Such DITs enable an administrator to arrange network objects according to the logical (e.g., business) relationships between various objects in the network. When an organization uses such a directory service, the resulting DIT typically embodies and resembles the arrangement of business groups within the organization. An example of a directory service incorporating this type of object arrangement is found within Novell Netware 4.1, wherein a network directory is divided at the highest levels into various administrative groups within an organization. Lower levels represent network objects associated with the particular groups designated at the highest level of the DIT.
Organizing a directory service of objects according to logical (business) grouping provides advantages over geographic grouping of objects when the directory service resources identified within the DIT are typically associated with particular business purposes. For example, a particular client database may be accessed exclusively by a sales department. It is advantageous that such a resource is not listed within, and thus cluttering, a portion of a directory service of objects that is accessed by non-sales users. A directory service model sub-divided at a highest level into organizational groups is particularly useful when most network resources are accessed at a relatively low cost. This is likely to occur only when the network resources and users are well connected via permanent, low cost, and high capacity links. On the other hand, in many organizations, resources associated with a given organizational group are distributed throughout the country or even the world, and these resources are accessed only at great cost.
Yet other known directory service arrangement schemes include DITs providing information relating to both location and organization. However, these known DITs lacked sufficient generality. In particular, a DIT for a corporation spanning a number of remote locations is initially divided according to location. At each location, the directory is sub-divided according to business unit. The specific implementations may vary from system to system depending upon how the system administrator sets up the DIT. In each case, the administrator attempts to minimize the impact of the costs of organizing the tree geographically versus logically.
In order to facilitate quick and efficient access to data, such as databases, directories, and programs, in a network extending to a number of remote locations, the data is replicated (i.e., stored at a number of locations within the network). For example, in a network comprising multiple local area networks (LANs) connected via non-permanent and/or relatively lower bandwidth wide area network (WAN) links, a replicated directory service of network resources may reside upon multiple machines within the communicatively remote LANs.
The use of an information unit to identify a geographic unit, subnetwork, or LAN within a network connected via one or more WAN links has been used in the Exchange Server and System Management Server products of Microsoft Corporation. Routers have also used a similar identification. The Network Link State and Open Shortest Path First protocols provide means for an administrator to assign costs to inter-network links. These costs are used by routers to determine the costs for various paths from a source node to a destination node in a network and use the computed costs to select an appropriate route. However, none of these prior art location-based solutions address or suggest solutions to the problem of designing and implementing directory services of network resources which present directory information in a manner that facilitates automated decision making for efficiently managing and carrying out network directory services.